Self-locking tamper proof strap



June 28, 1966 w. J. LlTwlN 3,257,594

SELF-'LOCKING TAMPER PROOF STRAP Filed March 21, 1965 2 I'Tl 2. s 4 (43Q T 43 2 4-4 394940 16.3 65 45 262360333 V 8\ Y\ f r e4 INVENTOR.

Wa 7%@ lz' wan www@ United' States Patent 3,257,694 SELF-LOCKING TAMPERPRGQF STRAP Walter Il. Litwin, 4465 N. Forestview Ave., Chicago, Ill.Filed Mar. 21, 1963, Ser. No. 266,899 8 Claims. (Cl. 24-16) Thisinvention relates to flexible or plastic straps and the like which areformed of nylon or polyethylene or similar material and is particularlydirected to a strap which upon being fastened cannot be unfastenedwithout evidence of tampering.

It has been found to be convenient, if not necessary, in certaininstances to provide a strap which cannot be reused. For example, inhospitals, the patients statistics are attached to the patient and it isof utmost importance in certain instances as with infants that this notbe removed. In sealing instruments or freight cars, a tamper proof sealis required which is inexpensive and easy to apply even by inexperiencedpersonnel with minimum of effort and without requiring the use of tools.A further important consideration is to provide a strap which lendsitself to mechanical production methods.

A general object of the invention is to provide a novel, simple andefficient self-locking strap.

A further object of `the invention is to devise a novel strap whichcomprises a plurality of cooperative locking means which collectivelyand individually serve to secure the strap from unfastening.

Another object of the invention is to devise a strap having a buckleportion formed with reverse passages to admit reversely extendinglengths of the strap tongue and wherein these passa-ges are separated byreinforcing braces which function to prevent prying the buckle apart towithdraw the tongue from the buckle without causing the buckle torupture and thus evidence lthat it has been tampered with.

More specifically the invention provides in one embodiment thereof astrap having a buckle having upper and lower tongue passages with toothcatching or engaging surfaces transverse to the passages and whichcooperatewith teeth disposed on opposite sides of a tongue portion ofthe strap to prevent withdrawal of the tongue portion from the passages.

These and other objects and advantages inherent in and encompassed bythe invention will become more readily apparent from the specificationsand the drawings wherein:

FIGURE 1 is a top plan View of one embodiment of the novel strap;

FIGURE 2 is a longitudinal section taken substantially on line 2-2 ofFIGURE l;

FIGURE 3 is a bottom view;

FIGURE 4 is a cross-sectional View taken generally on line 4-4 of FIGURE1;

FIGURE 5 is a side elevational view of the strap partly in section shownin its fastened or locked position;

FIGURES 6-8 illustrate a further embodiment of the invention; FIGURE 6being a top plan; FIGURE 7 being a longitudinal section takensubstantially on line 7 7 of FIGURE 6 and FIGURE 8 a side elevationalview partly in section showing the strap in fastened position.

Describing the invention in detail and having particular reference toFIGURES 1-5 of the drawings there is shown a flexible strap generallydesignated 2 formed of nylon or polyethylene or the like and having abuckle portion 3 at one end and an integral tongue portion 4 extendingtherefrom.

The tongue portion 4 has a tip end 5 which is formed to facilitate itsentry through the buckle passages 6, 7, 8 and 9 of strap channels 6a, 7awhich passages 6, 7, 8, 9 are developed between the horizontalcombination rein- 3,257,694 Patented June 28, 1966 forcing antitampersupport bars 12, 13 which are generally rectangular in cross-section(FIGURE 2) and are positioned substantially medially between the topwall 14 of the buckle and the bottom wall portions or base portion 15thereof.

The tongue 4 has an initial length 16 which is narrower and thinner thanits inner end portion 17. The tongue 4 is looped on itself and isadapted to be laced into the buckle through the passage 6 between theunderside 20 of the brace 12 and the side 21 of the inner end portion 17of the tongue 4 and the tongue 4 engages the catch side 23 of a tooth 24against the locking edge 25 formed on the inner edge of the inner endportion 17 of the tongue 4. The tooth 24, which holds the strap fromwithdrawing as it is laced through the buckle, projects into an apertureor opening 26 in the base portion 15 of the buckle 3, said opening 26being defined between the portion 17, the bottom wall 15 which isconnected with portion 17 and the interconnecting upright side walls 28,29 of the buckle 3, said walls 28, 29 merging with respectiveextremities of the top wall 14 of the buckle 3 and the braces 12, 13 andthe portions 15 and 17 and defining therewith the beforementionedpassages.

The tooth 24 has a forward ramp side 30 which facilitates its entry intoand through the passage 6 with attendant distortion or bending of thebrace 12 upwardly or toward the wall 14. It will be realized that uponthe tooth 24 being snapped behind the ledge or shoulder 25 it isdiflicult to withdraw the tongue from the buckle.

The placement of tooth 24 from the juncture 32 between i portions 16 and17 of the tongue is dimensioned to be substantially equal to thedistance from the shoulder 25 to the opposing edge 33 on the bottom wallportion 15 ofthe slot 26. The cross-sectional area of slot 6 andpassageway 6a is dimensioned to snugly admit passage of portion 17 ofthe strap therethrough and the juncture 32 forms a shoulder which seatsagainst the edge or wall portion 33 which is of a length equal to thewidth of the juncture shoulder 32 which prevents further movement of thestrap portion 17 through the buckle channel 6a.

The thinner and narrower leading strap portion 16 is bighted at 35 aboutthe outer edge 36 of the ledge 13 and reenters the buckle through ltheupper passages S and 9 and on its side 34 is provided with theoutstanding teeth 39, 40 which are spaced a distance substantially equalto the transverse spacing between the adjacent edges or shoulders 41 and42 of the coplanar ledges 12 and 13, said edges 41, 42 together with theadjacent upper thickened portions 43, 44 of the side walls 28 and 29dene an aperture or slot 45 which is in transverse or vertical registrywith the opening 26 from which it is shielded by the youter end strapsection 47 of the tongue portion 17.

The teeth 39 and 40 presen-t ramps 48, 49 facing toward the free end ofthe tongue t-o facilitate entry of the locking means 39, 40 throughpassage 8 as the outer end portion 5 zis pulled through and out of thebuckle through passage 9. These teeth 39, 40 present locking faces 50,51 and in the position of FIGURE 5, the face 51 engages shoulder or edge42 of the ledge 13 while the ramp 48 wedges against edge 42 of the ledge13 while the ramp 48r wedges against edge 41 urging the face or lockingmeans 51 against the edge 42 and simultaneously urges the section 54 ofthe tongue between the teeth 39, 40 upwardly, said section 54 having onits obverse side a plurality of locking means in the form of teeth 55which project upwardly and interengage with complementary teeth 56 onthe underside of the top wall 14 of the buckle. The locking faces 57 ofteeth 55 engage with and abut the locking faces 58 3 of teeth 56. If awedge should be applied against teeth 55 a downward force is exertedurging teeth 39, 40 into engagement against tongue section 47 and ledges12 and 13. If a force is applied to section 47 and/ or teeth 39, 40 theteeth 55, 56 will hold.

It will be observed that the teeth 56 are in alignment with openings 45,26 so that in the molding process of the buckle 3 the core die isadapted to be easily inserted and withdrawn. Opening 45 is smaller thanopening 26 for the same reason and to form the ledges 12, 13 and theside ramps 60, 61 which narrow the passageway 7a codimensional withportion 16 of the strap.

It will be readily apparent that any attempt to pry the teeth apart orto forcibly withdraw the tongue from the buckle will rupture the partsor evidence tampering. Surface 20 extends under ramps 60, 61 and theledge 13. The ledges `or bars 12 and 13 may be notched at 63, 64 to tearthe bars from the walls 28, 29 to evidence tampering.

In considering the advantages of this tamper-proof strap, it is to notedthat the cross-sectional area of the strap portion `17 is only slightlyless than the crosssectional area of the entrant passage 6a and thecrosssectional area of the strap portion 16 is only slightly less thanthe cross-sectional area of the entrant passage 7a to provide a snug inplace fitting of the strap 4 in the buckle 3, and the walls 28, 29 ateach of their ends taper from the top wall 14 outwardly and downwardlytoward the bars 12 and 13 and bottom wall 15 to add strength to theconstruction of the buckle 4, the ends of the walls 28, 29 adjacent theopening or passage 7 and strain bar 13 being of sufficient height andlateral outward extent in the area of the bight to enclose the strapthereat in such a manner as to shield or protect the strap at its bight35 so that no grip or object could be forced therewith without damagingthe side walls of the buckle to evidence tampering.

The embodiment of FIGURES 6, 7, and 8 illustrates a similar arrangementalthough simplified. The strap cornprises a buckle at one end of atongue 101 which has a curved leading portion 102 to facilitate itspassage through the lower and upper passageways 103 and 104 of thebuckle, said passages being formed by top and bottom portions 105, 106;side wall portions 107 and 108 and an intermediate ledge or locking bar109, said wall portions joining the ends of the parts 105, 106 and 109.The tongue 101 has an outer end portion 110 formed with teeth 111recessed in one side 112 thereof. The toothed outer end portion passesover the bottom wall 106 and continues through the passage 103 with itstiat side 115 engaging the underside 116 of the transverse support baror ledge 109. The teeth have their ramp sides 117 sliding over the bevelor tapered edge 119 on the inner end portion 120 of the tongue, Saidedge 119 forms with the side .walls and wall portion 106 a bottomopening or slot 121 which normally would be against the users wrist. Thestrap is bighted at 122 about the outer edge 123 of the ledge 109 andthen passes over the top side 125 of ledge 109 through passage 104 andunder the top wall 105 and has several of its teeth 111 engaging withcompanion teeth 128 formed on the bottom of the top wall in verticalalignment with the bottom buckle aperture 121. The upper exiting endportion of the strap passes over the lower entering outer end portion ofthe strap and bears ythereagainst and exits through the passage 113.

The strap has an intermediate portion 130 which in the present instancemay be formed with an appropriate longitudinal rectangular slot 131 toadmit an identity card therein which is visible through the outer Windowportion 132 of the portion 130.

It will be observed that novel strap or loop safetyl devices have beendisclosed and that in view of these disclosures various other forms ofthe invention will become readily apparent to those skilled in the artwithin the scope of the following appended claims.

I claim:

1. A iiexible strap comprising a tongue portion having a free end and abuckle portion joined with the tongue portion, the buckle portion havinga top wall, side walls, a bottom wall, and wall means disposed `betweenthe :walls and defining a pair of tongue receiving channels, said topand bottom walls extending generally parallel to the plane of thetongue, said free end of the tongue having yfirst and second sectionsbeing laceabie back over on itself around the wall means through thechannels to place a first section of the free end of the tongue in onechannel and a second section of the tongue in the other channel inlocked position and having means thereon interlocking with the top walland forming a loop with the buckle portion in the locked position of thestrap.

2. The invention according to claim 1 and said bottom wall having anaperture, said' tirst section having a toothed element extendable intothe bottom wall aperture for limited movement of the first section inthe buckle.

3. The invention according to claim 1 and said wall means having anintermediate wall aperture 1 and said wall means having an intermediatewall aperture and the second section having locking structure extendableinto the intermediate wallA aperture for limiting movement of saidsection in the buckle.

4. A flexible tamper proof strap comprising a tongue and a buckle, saidbuckle having a top wall, a bottom wall and a pair of side walls, anintermediate wall between the top and bottom walls and connected withthe side walls and delining a pair of generally parallel passages, saidintermediate ywall having an aperture aligned beneath said top wall,said bottom :wall having an aperture in alignment with the aperture inthe intermediate wall, said tongue having -a first section connectedwith the bottom wall and extendable in one passage over the bottom wallaperture and having a bight section extendable around the intermediatewall and having a second section extendable in the other passage overthe intermediate wall aperture and out of .the buckle said secondsection and said top wall having interlocking means thereon formaintaining the strap in a locked tamper proof condition.

5. The invention according to claim 4 and the side walls having portionsextending outwardly of `the buckle portion and encaseable about thebight portion in shrouding tamper proof relation therewith.

6. The invention according to claim 4 and said first section being ofgreater cross sectional area than said second section limiting movementof the sections in the channels.

7. A flexible strap comprising a tongue portion and a buckle portion,said buckle portion having a top wall, side lwalls, and a bottom wallhaving an aperture, an intermediate 4wall connected with the side wallsand between the top and bottom walls and in alignment with said apertureand delining a pair of upper and lower tongue passages, said top wallhaving an internal downwardly directed toothed segment to one side ofthe intermediate wall and in alignment with the aperture, said tongueportion being connected with the buckle and having a free end with atoothed portion extendable through the lower passage and about the otherend of the intermediate wall through the upper passage and out thebuckle portion for attendant interlocking of the toothed portion withthe toothed segment.

8. A flexible tamper proof strap comprising interconneoted tongue andbuckle portion, said tongue portion having a free end portion havingopposed top and bottom sides with teeth-like means projecting from eachside, each of said teeth-like means being generally in alignment withone another, the buckle portion having side walls and an uppertransverse wall and a pair of longitudinally spaced apart lowertransverse walls spaced vertically from and generally parallel to theupper wall,

5 the upper and lower walls being connected to the side walls anddeiining a longitudinally extending tongue passage therebetween forreception of the free end portion of the Itongue therein, each lowerwall being spaced genrally outwardly of the vupper wall in pyramidfashion therewith and defining an aperture between the lower wallsbeneath the upper wall, the upper wall being provided on its inside withmeans for locking engagement with the teeth-like means on one side ofthe tongue free end portion with the teeth-like means on the other sideof the tongue free end portion being received in the aperture forrestricting movement of the tongue lfree end portion through thepassage.

References Cited by the Examiner UNITED STATES PATENTS I 2,915,26812/1959 Wrobel. 2,977,145 3/196i1 Rifkin. 3,068,600 12/1962 Blanchet40-316 3,102,311 9/1963 Martin et al. 24-305 X FOREIGN PATENTS 1,288,1282/1962 France. 508,037 1/ 1955 Italy.

WILLIAM FELDMAN, Primary Examiner.

D. GRIFFIN, Assistant Examiner.

1. A FLEXIBLE STRAP COMPRISING A TONGUE PORTION HAVING A FREE END AND ABUCKLE PORTION JOINED WITH THE TONGUE PORTION, THE BUCKLE PORTION HAVINGA TOP WALL, SIDE WALLS, A BOTTOM WALL, AND WALL MEANS DISPOSED BETWEENTHE WALLS AND DEFINING A PAIR OF TONGUE RECEIVING CHANNELS, SAID TOP ANDBOTTOM WALLS EXTENDING GENERALLY PARALLEL TO THE PLANE OF TONGUE, SAIDFREE END OF THE TONGUE HAVING FIRST AND SECOND SECTIONS BEING LACEABLEBACK OVER ON ITSELF AROUND THE WALL MEANS THROUGH THE CHANNELS TO PLACEA FIRST SECTION OF THE FREE END OF THE TONGUE IN ONE CHANNEL AND ASECOND SECTIONOF THE TONGUE IN THE OTHER CHANNEL IN LOCKED POSITION ANDHAVING MEANS THEREON INTERLOCKING WITH THE TOP WALL AND FORMING A LOOPWITH THE BUCKLE PORTION IN THE LOCKED POSITION OF THE STRAP.